A synthetic approach to a dicyclobutadieno benzene is being explored which should furnish a number of examples of this highly interesting series of compounds bearing protons directly bound to the pi-framework. The target compound constitutes a formally highly activated yet aromatic pi-electron system. Similar approaches will be instituted en route to a dihydro analog, a cyclobutadieno cyclooctatetraene. We are currently instituting a collaborative project on the 1,5,9-cyclododecatriyne-hexaradialene potential energy surface. The photoelectron spectrum will be interpreted by quantum mechanical calculations and we will attempt to generate the radical anion. In addition, a high pressure reaction is being tested as a potential way of effecting ring-closure to tricyclobutabenzene. An intramolecular trapping experiment will be conducted to prove the existence of a complexed tricyclooctatetraene in the gas phase. Using our preliminary data and our newly developed synthetic methodology we are planning synthetic schemes en route to other activated polycyclic hydrocarbons of known carcinogenic potential, e.g., cyclobutabenzanthracene, and cyclobutabenzpyrene. The Ames test will be applied in preliminary mutagenicity screenings.